Investigation of calcium sulfate as the carrier of platelet-rich plasma

Objectives: To Investigate calcium sulfate (CS) as a carrier of platelet-rich plasma (PRP) to treat the bone defect for the dental implant placement. Methods: PRP was prepared according to the method described by Kim. Four defects, two on each side, were created in the mandibles of each of five dogs. In each dog, the two anterior defects were paired, with one of the defects placed CS (Osteoset, Wright Medical Technology, USA) and PRP mixture (A group) and the other defect unfilled as a control (B group). The two posterior defects were paired, with one of the defects placed another CS/PRP combination (C group) and CS in the other defect(D group). Bone scintigraphy was performed 2, 4, and 6 weeks after the surgery to investigate the variance of the bone metabolism activity. One dog was randomly chosen to be sacrificed 8 weeks postsurgically for histological study. Meanwhile, the other four dogs were subject to the implantation of 48 dental implants. They were then sacrificed 3 months after dental implant placement for histomorphometric study. Results: Concerning bone metabolism activity, the A group showed higher values at 2, 4, and 6 weeks after the surgery than B group, while the C group achieved higher values than the D group only at 2 weeks. The histological observation showed that complete CS resorption in all the treated defects and similar bone maturity among different groups was achieved. The histomorphometric study of the osseointegration revealed a higher percentage of bone-to-implant contact (P=0.024) in the A group (56.84±5.17%) compared with B group (41.48±4.47%), but no statistically significant difference (P=0.979) was detected between the C (50.03±4.18%) and D group (49.97±6.62%). Conclusion: CS may be an ideal carrier for PRP to fill the bone defects prior to dental implant placement.